Index A Airfoil characteristics, argument for, 99 Angle of attack, 75 Axial compressor, distorted inlet flow propagation in, prediction of, 77–79 results compressor characteristics, 96–98 inlet distorted velocity coefficient, 87–88 inlet incident angle, 88–91 lift and drag coefficients, 86 propagation of distortion level, 91–95 theoretical formulation, 79–86 Axial compressor, propagation of inlet flow distortion in, using integral method, 1–3 numerical method equations, 11 4th-order Runge-Kutta Equations, 11–12 results, 13–17 asymptotic behavior results, 17–20 compressor performance and charac- teristic, 23–26 critical distortion line, 22–23 mass flow rate, 20–22 theoretical formulation, 3–4 distorted region, 7–8 entire region, 9–10 forces, 5–7 integral equations, 10–11 undistorted region, 8 velocity and pressure, 4–5 C CFD codes, 78 Chebyshev curve fitting, 101–106 Complex flows, numerical simulation of, 78 Compression system, 77 Compressor characteristics, 96–98 performance, 57–58 three dimensional flows in, 41 Critical distortion line, 3, 35–39 application of, 45–46 D Dimensionless velocity components, 43 Distorted inlet flow, 43 Distorted inlet flow propagation in axial compressor, prediction of, 77–79 results airfoil characteristics, argument for, 99 compressor characteristics, 96–98 inlet distorted velocity coefficient, 87–88 inlet incident angle, 88–91 lift and drag coefficients, 86 propagation of distortion level, 91–95 theoretical formulation, 79–86 Distortion level, 87 Drag-to-lift ratio, 64–68 F Flaming of refueling leakage near inlet and stall prediction of in-flight com- pressor, 41–42 compressor characteristics, 50–51 inlet distorted region size (ξ (0) ), effects, 53–55 rotor blade speed (σ), effects, 52–53 computational domain, 43–45 critical distortion line, application of, 45–46 inlet flow condition, 42–43 Flow non-uniformities, 2 Force field, 79 Fortran Program critical distortion line, 35–40 integral method, 28–34 132 Index G Gas turbine engine, 57 Greitzer’s B-parameter model, 107, 108, 110 Greitzer’s instability flow model, para- metric study of, using Taguchi method, 107–108 mathematical model, 108–110 numerical methods, 110–114 results with parameters B, G and K, 115–118, 120–121 with parameters B, G and L c , 118–120, 118–121 Greitzer’s model, 123–129 H Helmholtz frequency, 109 I In-flight compressor, stall prediction of, 41–42 compressor characteristics, 50–51 inlet distorted region size (ξ (0) ), effects, 53–55 rotor blade speed (σ), effects, 52–53 computational domain, 43–45 critical distortion line, application of, 45–46 inlet flow condition, 42–43 Inlet distorted region size, 53–55 Inlet distorted velocity coefficient (α(0)), 68–72, 87–88 Inlet distortion propagation in compressor, parametric study of, 57–58 methodology, 59–60 results, 60–64 drag-to-lift ratio (K), 64–68 X-axis inlet distorted velocity coeffi- cient (α (0)), 68–72 inlet flow angle (θ 0 ), 72–73 Inlet flow distortion, 1–2 and integral method, 42–50 Inlet flow distortion, propagation of, in axial compressor using integral method, 1–3 numerical method equations, 11 4th-order Runge-Kutta Equations, 11–12 results, 13–17 asymptotic behavior results, 17–20 compressor performance and charac- teristic, 23–26 critical distortion line, 22–23 mass flow rate, 20–22 theoretical formulation, 3–4 distorted region, 7–8 entire region, 9–10 forces, 5–7 integral equations, 10–11 undistorted region, 8 velocity and pressure, 4–5 Inlet flow angle (θ 0 ), 72–73 Inlet incident angle, 88–91 Integral method, 46–50 and inlet distortion propagation in compressor, 57–73 for prediction of distorted inlet flow propagation in axial compressor, 77–79 results, 86–99 theoretical formulation, 79–86 L Lift and drag coefficients, 86 M Mass flow in inlet, loss of, 45 N NACA 65-series airfoil, 86 Navier-Stokes equation, 1, 59 Non-dimensional mass flow rate, 51 P Parallel compressor model, 2 Propagation of distortion level, 91–95 R Reynolds number (R e ), 86 Rotor blade speed, 52–53 Runge-Kutta equations, 4th-order, 11–12, 86, 107, 110–111 S Stall prediction of in-flight compressor, 41–42 Index 133 compressor characteristics, 50–51 inlet distorted region size (ξ (0) ), effects, 53–55 rotor blade speed (σ), effects, 52–53 computational domain, 43–45 critical distortion line, application of, 45–46 inlet flow condition, 42–43 integral method, application of, 46–50 T Taguchi’s quality control method, 42, 57 Greitzer’s instability flow model, parametric study of, 107–108 mathematical model, 108–110 numerical methods, 110–114 results, 115–118, 118–120, 120–121 and inlet distortion propagation in compressor, 57–73 Tangent of flow angle in inlet, 52 Turbomachinery, 1 V Vapor-air mixture, 42 . Equations, 11– 12 results, 13–17 asymptotic behavior results, 17 20 compressor performance and charac- teristic, 23 26 critical distortion line, 22 23 mass flow rate, 20 22 theoretical formulation,. Equations, 11– 12 results, 13–17 asymptotic behavior results, 17 20 compressor performance and charac- teristic, 23 26 critical distortion line, 22 23 mass flow rate, 20 22 theoretical formulation,. coefficient (α(0)), 68 – 72, 87–88 Inlet distortion propagation in compressor, parametric study of, 57–58 methodology, 59 60 results, 60 64 drag-to-lift ratio (K), 64 68 X-axis inlet distorted